IGCSE/GCSE/O & A Level/IB/University Student Forum
Qualification => Others => GCSE => Topic started by: astarmathsandphysics on October 06, 2008, 11:06:45 am
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Post your GCSE questions here to get the answers back asap from someone with 3 maths/physics degrees.
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I tried starting a new topic but it's not working for me. Anyways plz help me
The second part of the question needs help.
Q.The air in a bicycle tyre has a volume of 1000cm3 and a pressure of 2.5 atmospheres. If the air is released ( at the same temperature) so its pressure is 1 atmosphere, what is the volume of the air?
This part needs help
A bicycle has a volume of 100cm3 and is now used to pump up the tyre. After 1 stroke of the pump, what is the presure in the tyre?
Thanks
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the constant here is = (1000/2.5) =400.
there fore after 1 stroke the volume increases by 100 cm3, thus new volume = 1100.
but because the constant does not change, therefore, 1100/x = 400
=> x = 1100/400 = 2.75 atm.
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How did I miss this question for so long
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hm..!!
i guess you did not notice it!!
u are too busy person rite??
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v busy
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the constant here is = (1000/2.5) =400.
there fore after 1 stroke the volume increases by 100 cm3, thus new volume = 1100.
but because the constant does not change, therefore, 1100/x = 400
=> x = 1100/400 = 2.75 atm.
hey ansh!!!
u've done one thing wrong here....
according to the boyle's law constant = pressure*volume
so, k=1000*2.5 = 2500
thus,
p= k/v
=>p=2500/1100
=>p=2.27 atm
am i right sir???
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You were supposed to work out the volume of the air I think when the pressure is reduced from 2.5 atm to 1.
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is it 2500/2600 = 0.9?
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that was the first part...i think nid said she wanted help in the second part...
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is it 0.9?
u talking abt the first or second part??
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I tried starting a new topic but it's not working for me. Anyways plz help me
The second part of the question needs help.
Q.The air in a bicycle tyre has a volume of 1000cm3 and a pressure of 2.5 atmospheres. If the air is released ( at the same temperature) so its pressure is 1 atmosphere, what is the volume of the air?
This part needs help
A bicycle has a volume of 100cm3 and is now used to pump up the tyre. After 1 stroke of the pump, what is the presure in the tyre?
Thanks
its ritten the second part needs help.
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so wats the correct answer then?? ???
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pV=k so 2.5*1000=k so V=2500/p but p is now 1atm so V=2500cm£
Some of the air escaped to the atmosphere
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sir cud u do the second part as well??
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the V is 2500cm3..when 100cm3 gas is added V = 2600cm3
pressure = k/2600
k=2500
pressure = 0.9
0.9<1
pressure decreases from 1 to 0.9 volume increases from 2500 to 2600
i suppose this is the way if the second part is a continuation
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see if the second part is a continuation...den this is ok...if not den mine is ok....
so how do we decide???where is nid???she might be knowing the right answer!!
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The second part is comletely diff
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Well, I think I got this question from a gcse textbook....I think aadi it's from the one I gave you. Check kar....gas laws mein....i think it's from there.....So basically even I forgot abt this question. I really don't know what the initial volume and pressure should be taken as.
I would go for what adi's done..........
aadi check that book again
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hm..!!
will these type of q's come in IG papers too!???
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hm..!!
will these type of q's come in IG papers too!???
y not?...its not that difficult.
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hm..!!hope so they dont come in alt. to pracs!!
By the way watyou studying for them???
ne imp topics???
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abbe...woh book mein dekh...question hoga usme,...answer bhi hoga
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abbe...woh book mein dekh...question hoga usme,...answer bhi hoga
cant find it..
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cant find it..
chor de......mujhe yaad hi nahi phir...kaha se aaya yeh question
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which book!!
e-book??
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i need help with momemntum questions!!! i have my ohy theory this monday....
:(:(:( :'(
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i need help with momemntum questions!!! i have my ohy theory this monday....
:(:(:( :'(
aren't you doing AS level? wrong forum :P
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sawry...my bad!!
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dont know y all a and as level people post most of there queries in here!! :P
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cause its not used much (this thread) so any posts here are noticable .. thus the many random doubts .. naughty naughty members :P :P
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Would be easier for me if all the maths and physics questions were in the same topics. Else I might not find them
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heyy sir .. long time no see ;D
so like a similar topic (like this one) in every board?
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Yes |I did create one but people make their own topics. It matters not. They are easier to find on my mobile phone so I post to say I will answer when I get home then look for my last posts when I get home.
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please i need someone to urgently solve this question!!...integration:
the limits are 1 and 0...it is
x.f(x)
and f(x)= 2(x+2)/5
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fx--> 2x+4/5
i dunno how to use the integration sign
f integration (x)--->2x/5 dx + 4/5dx
x2/5 +4/5x
sorry i made an error in the previous integration
but u still don't get the ans......i will try agn
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fx--> 2x+4/5
i dunno how to use the integration sign
f integration (x)--->2x2/5X2 + 4/5x
---> x2+4x/ 5
substitute upper and lower limits
& then subtract lower limit from upper limit
2(1)2+ 4(1)/ 5=6/5
2(0)2+ 4(0)/ 5= 0
6/5-0=6/5
I think this is how it is to be done
the answer is 8/15
:( :S
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thank you waisay!! :)
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edited my post...but still not that ans
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edited my post...but still not that ans
nevermind lets just hope nuthin of the sort cumes in my test! :-X
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xf(x)= 2x(x+2)/5=2x^2/5+4x/5 integrate to get 2x^3/15+2x^2/5
then put limits in to get (2/15+2/5).0=8/15
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but it's 2(x+2)/5 nd not 2x(x+2)/5
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It says x.f(x)
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It says x.f(x)
sorry my bad
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xf(x)= 2x(x+2)/5=2x^2/5+4x/5 integrate to get 2x^3/15+2x^2/5
then put limits in to get (2/15+2/5).0=8/15
omg thank you so much dude!!!
:) :D
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Spam?
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Did similar triangles and vector crap like this a long tym ago, so culdnt solve it for my brother. So Paulie please help. I am writing down the question and then attaching the picture
In the figure, the lines ST, PQ and OR are paralle. OPS, OQT and RQS are straight line and OR= 3a OP= b and PS=2b and OQ= 2a+b . The underlined letters are all vectors.
Express in terms of a and b
(a) (i) PQ (ii) QR (iii) QT (iv) ST I did find (a) (i) and (a) (iii) but not the rest
(b) (i) the area of triangle OPQ / area of triangle SPQ
(ii) the area of triangle OPQ / area of triangle OST
(iii) the area of triangle OPQ / area of triangle ORQ
And the answers are:
(a) (i) 2a (ii) a-b (iii) 4a+2b (iv) 6a
(b) (i) 1/2 (ii) 1/9 (iii2/3)
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here
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hey wht did u mean by the lambda sign ?? ???
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lambda is a parameter
lambda and mu label the points on a line so by finding them you can find the point